I don't know about this particular boat. Core saturation does not happen overnight, but rather over long periods of time. Think several years. It's easy for water to get in. As already mentioned, improperly sealed fasteners are a source. In fact, this is probably the major source. There is a good reason for the advice to drill holes oversize, fill with epoxy, then drill the correct size - it seals the core from water. The skin being built too thin is another cause (it can fracture and let water in). So is storing the boat uncovered over several seasons. Or not having it leveled so water can drain out. Once water is in your fiberglass-encapsulated core, its hard for the water to get back out. According to one book I have (Fiberglass Boat Repair Manual by Alan Vaitses - older but lots of good info), it can take 6 to 15 years for total saturation, and the saturation can go unnoticed until it's well advanced.
see page 83 here :
http://books.google.com/books?id=uNl...ration&f=false